At present, in the process of manufacturing a liquid crystal display panel, it is required to perform an electrical test on a flexible printed circuit (FPC) board of the display panel. In a production line of the display panel, one approach to carrying out the electrical test is to plug the FPC board into a printed circuit board assembly (PCBA) of an electrical testing device so as to test product functions. This approach suffers from such defects as high requirements of an operator's operating capability, difficult plugging operation, long operation time (about 30 seconds), high misjudgment rate (about 1%) caused by poor plug-in connection, high scrap rate for PCBAs (about one PCBA scrapped for 100 pieces), and high cost for a single piece. As a result, the product cost is high and a first pass yield (FPY) is adversely affected.